1. Technical Field of the Invention
The present invention relates to a display unit for a vehicle and an input device therefor. More particularly, the present invention relates to a display unit for a vehicle suitable for use, for example, in a car navigation system, and which allows global control of various functions of the vehicle's amenities using a single input device.
2. Description of Related Art
A car navigation system has been proposed in which various switches are graphically displayed on a monitor screen so that the driver can select switches by moving a cursor on the screen using a joystick. Such a vehicle display unit is demonstrated by the technique shown in FIGS. 16 through 18, which is disclosed in JP-U-2-54616. A description of this technique is provided below with reference to FIGS. 16-18, to facilitate a better understanding of the present invention.
As shown in FIG. 16, a switch selection screen 43 is displayed on a display monitor 42 attached in a position suitable for the driver's viewing. A "cross-hair" cursor 46 is controlled by means of a mouse 44 (FIG. 17), or the like, which is provided on the floor console. The operation of this system can be explained using a specific example, in this case: changing the temperature setting of the automatic climate control.
For example, when the driver wishes to change the temperature setting of the climate control, the driver must first select the "air-conditioning" menu from the initial screen (FIG. 18A) on which various switches 45 for "air-conditioning", "radio", "navigation", etc., are displayed. Then, from the "air-conditioning" menu display the driver selects "temperature" (FIG. 18B). Finally, on the next screen the driver can reset the value of the temperature (FIG. 18C). As can be readily seen, in this particular example the driver has to go through three operations, i.e., three "mouse-clicking".
In the aforementioned vehicle display unit, the video device performs single-plane display so that screens are displayed in a hierarchical structure. Accordingly, the driver must carry out several operations in order to select a desired switch. Specifically, the driver first needs to manipulate the cursor to select the required mode from the mode selection screen. Then the driver needs to select the desired function from the mode screen. Finally, the driver has to select the desired setting from the function screen.
In this manner, substantial time is required for selection because it is necessary for the driver to repeatedly move the cursor and click the mouse to arrive at the desired mode, function and setting screens. Furthermore, in the case where the mode selection screen is to be changed, the driver cannot see the arrangement of the switches on the next screen before the next screen having the arrangement of switches is actually displayed. That is, for example, in any particular instant the driver may wish to change the temperature setting, but a different mode screen, such as a "radio" screen or the like, may be displayed because of a previous operation or of the driver's mistaken operation. Under such condition, the driver cannot arrive at the temperature setting screen until the driver exits the displayed mode and changes to the "air-conditioning" mode.